;p10.1.1.asm
assume cs:code

stack segment
 db 16 dup(8)
stack ends

code segment
        mov ax,4c00H
        int 21h
    start:  
        mov ax,stack
        mov ss,ax   
        mov sp,16 ; 栈顶

        mov ax,0
        push ax ;sp=sp-2
        mov bx,0
        ret      ; (ip)= (ss * 16) + (sp) ss为stack 段地址  
                 ; sp 设置为为10H
                 ; push ax sp=sp-2(一个子为两个字节)  sp为EH
                 ; (IP) = ((ss) * 16 + (sp)) 获取栈的中ss:[14]的
                 ; (sp)=(sp)+2  sp 为10Hcd
code ends
end start